package main

//var graph = make(map[string]map[string]bool)
//
//func addEdge(from, to string) {
//	edges := graph[from]
//	if edges == nil {
//		edges = make(map[string]bool)
//		graph[from] = edges
//	}
//	edges[to] = true
//}
//
//func hasEdge(from, to string) bool {
//	return graph[from][to]
//}
